This project will measure the uniaxial compressive stress- strain relationship of a suite of cemented tungsten-carbide samples. Because of its high strength, cemented tungsten carbide is used as a key structural component in the design of state-of- the-art high pressure multi-anvil apparatus capable of experimentation up to 25-30 GPa. Optimal design of high-pressure apparatus is hampered by a lack of information about the fundamental rheology of this material under conditions that mimic the conditions imposed on the material in such high-pressure systems. This project is intended to provide the necessary data, and the results will also enable finite element analysis of new designs for improved high-pressure apparatus. Experimental capabilities in the ultra-high range of static pressure are necessary for basic research in earth sciences and materials science.